When you manually change a CFrame , Roblox physics might think you collided with something at 2000 mph, throwing your character into the sky. Osmium scripts claim to "freeze" velocity before the teleport and unfreeze after:
In , teleportation scripts manipulate the HumanoidRootPart of the player's character. By programmatically changing the CFrame (Coordinate Frame) of this part, the script "snaps" the player to new coordinates instantly.